Module Name: src
Committed By: wiz
Date: Thu Jul 8 21:33:02 UTC 2010
Modified Files:
src/share/man/man4/man4.x86: balloon.4
Log Message:
New sentence, new line. Remove trailing whitespace. Other minor fixes.
To generate a diff of this commit:
cvs rdiff -u -r1.1 -r1.2 src/share/man/man4/man4.x86/balloon.4
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/share/man/man4/man4.x86/balloon.4
diff -u src/share/man/man4/man4.x86/balloon.4:1.1 src/share/man/man4/man4.x86/balloon.4:1.2
--- src/share/man/man4/man4.x86/balloon.4:1.1 Thu Jul 8 20:00:24 2010
+++ src/share/man/man4/man4.x86/balloon.4 Thu Jul 8 21:33:02 2010
@@ -1,4 +1,4 @@
-.\" $NetBSD: balloon.4,v 1.1 2010/07/08 20:00:24 christos Exp $
+.\" $NetBSD: balloon.4,v 1.2 2010/07/08 21:33:02 wiz Exp $
.\"
.\" Copyright (c) 2010 The NetBSD Foundation, Inc.
.\" All rights reserved.
@@ -28,7 +28,7 @@
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
-.Dd July 06, 2010
+.Dd July 6, 2010
.Dt BALLOON 4 xen
.Os
.Sh NAME
@@ -42,9 +42,10 @@
driver can be enabled to allow the Xen hypervisor to dynamically
resize the amount of RAM a
.Nx
-VM is allowed to use. This allows the hypervisor to manage RAM more
+VM is allowed to use.
+This allows the hypervisor to manage RAM more
efficiently, similar in spirit to how the
-.Nx
+.Nx
kernel would manage RAM wrt processes, with
.Xr uvm 9 .
.Pp
@@ -52,13 +53,13 @@
.Nm
driver negotiates domain VM memory allocation change requests from
the Xen hypervisor, by reserving "pinned" memory for itself from the
-NetBSD
+.Nx
.Xr uvm 9
subsystem.
.Pp
There are two methods to notify the
.Nm
-driver of memory allocation change requests.
+driver of memory allocation change requests.
.Bl -tag -width "Xr sysctl 3" -offset indent
.It xenbus
In the xenbus method, the change notification originates outside the
@@ -67,7 +68,8 @@
.It Xr sysctl 3
In the
.Xr sysctl 3
-method, the change notification originates from within the VM. Two
+method, the change notification originates from within the VM.
+Two
.Xr sysctl 7
nodes are provided:
.Bl -ohang -width kern.xen.balloon.current
@@ -76,18 +78,21 @@
currently allocated to the VM.
.It Va kern.xen.balloon.target
This node can be written to, and sets a new target memory reservation,
-in pages. Note that targets set this way from within the VM do not
-reflect in the hypervisor. This is therefore a less preferred way to
-use the
+in pages.
+Note that targets set this way from within the VM do not
+reflect in the hypervisor.
+This is therefore a less preferred way to use the
.Nm
.El
.El
.Pp
In either case, once a new allocation target is set, the balloon
driver thread asynchronously attempts to reach this target in discrete
-steps. Every step, if it fails, is tried more than once. When the
-target is reached, the thread goes back to sleep, waiting for a new
-incoming target. If it is not reached, the target is updated to
+steps.
+Every step, if it fails, is tried more than once.
+When the target is reached, the thread goes back to sleep, waiting
+for a new incoming target.
+If it is not reached, the target is updated to
reflect the value after the last successful step.
.Sh EXAMPLES
.Bd -literal
@@ -98,7 +103,7 @@
#
# # Change the current target to 30000 kernel pages.
# sysctl -w kern.xen.balloon.target=30000
- kern.xen.balloon.target: 32512 -> 30000
+ kern.xen.balloon.target: 32512 -\*[Gt] 30000
#
.Ed
.Sh SEE ALSO
@@ -113,7 +118,9 @@
.An Cherry G. Mathew Aq che...@zyx.in
.An Jean-Yves Migeon Aq j...@netbsd.org
.Sh CAVEATS
-VMs can be inadvertently crashed/panic()ed by over expanding the
+VMs can be inadvertently
+.No crashed/ Ns Fn panic Ns ed
+by over expanding the
balloon allocation, creating extreme OS memory pressure.
.Sh BUGS
.Fn xenmem_get_maxreservation
